• Isotopic fractionation by diffusion in groundwater

    In the absence of other fractionation processes, and when expressed as a fractionation curve (isotopic enrichment and depletion as a function of concentration), diffusive fractionation in groundwater is generally bounded by the behavior in end‐member regimes, e.g., as in the case of a thin aquifer, thick aquitards, and fast flow parallel to the bedding plane, wherein dilution stems principally from diffusive

    Comparative study of granitic and sedimentary

    Comparative study of granitic and sedimentary groundwater colloids by flow-field flow fractionation coupled with ICP-MS. T. Saito * a, T. Hamamoto b, T. Mizuno c, T. Iwatsuki d and S. Tanaka† b a Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakata Shirane, Tokai-mura, Ibaraki 319-1195, Japan.

    Diffusive fractionation of <supscr>3</supscr>H and <supscr

    significant diffusive fractionation along principle flow paths can lead to the same 3H-3He apparent age for post-1950, prebomb peak and postbomb peak groundwater. Where such nonunique apparent age dates are plausible, additional hydrogeologic information may be necessary to assess the groundwater

    Comparative study of granitic and sedimentary

    14.05.2015· Size distribution and elemental compositions of colloids in granitic and sedimentary deep groundwater were determined by flow-field flow fractionation (Fl-FFF) combined with inductively coupled plasma mass spectrometry (ICP-MS). Great care was taken to examine colloids over a wide range of size and to detect trace elements associated with them. In the granitic groundwater organic

    Noble gas fractionation during subsurface gas migration

    15.09.2016· These studies illustrate the results of noble gas fractionation during two-phase flow of natural gas through groundwater. The first data set contains samples of gas composition from a continuous gas emplacement process at Bravo Dome, NM. The second and third data sets contain dissolved gas measurements from shallow groundwater in the Marcellus and Barnett shales. The observed distributions in these groundwater areas are likely the result of multiple gas

    Chromium Isotope Fractionation During Reduction of Cr(VI

    Chromium isotopes are potentially useful indicators of Cr(VI) reduction reactions in groundwater flow systems; however, the influence of transport on Cr isotope fractionation has not been fully examined. Laboratory batch and column experiments were conducted to evaluate isotopic fractionation of Cr during Cr(VI) reduction under both static and controlled flow conditions. Organic carbon was used to reduce Cr(VI) in simulated groundwater

    Estimation of groundwater temperature from 18O

    01.10.2019· In more generalized way for any gently dipping confined aquifer system, regional groundwater flow will be definitely gravity driven advection but in micro scale, different isotopomers of water will also fractionate depending upon its thermal stability regime due to incremental geothermal heat budget down dip. This physical fractionation of different isotopomers of water can be

    2.6 Stable Isotopes The Groundwater Project

    However, fractionation processes result in variations in isotopic composition of precipitation, and sometimes these variations can be used to identify conditions under which the groundwater recharge occurred (Figure 8). Other factors being equal, the isotopic composition will be more depleted in heavy isotopes during heavy rainstorms than during lighter storm events. So, if groundwater recharge

    Chapter 2: Fundamentals of Isotope Geochemistry

    These result from runoff mechanisms that include, but are not limited to, saturation-excess overland flow, Hortonian overland flow, near-stream groundwater ridging, hillslope subsurface flow through the soil matrix or macropores, and shallow organic-layer flow. Knowledge of hydrologic flowpaths in catchments is critical to the preservation of public water supplies and the understanding of the

    Comparative study of granitic and sedimentary

    Comparative study of granitic and sedimentary groundwater colloids by flow-field flow fractionation coupled with ICP-MS. T. Saito * a, T. Hamamoto b, T. Mizuno c, T. Iwatsuki d and S. Tanaka† b a Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakata Shirane, Tokai-mura, Ibaraki 319-1195, Japan.

    Diverse fractionation patterns of Rare Earth Elements in

    15.01.2020· Rare earth element concentrations, speciation, and fractionation along groundwater flow paths: the Carrizo sand (Texas) and upper Floridan aquifers. K.H. Johannesson (Ed.), Rare Earth Elements in Groundwater Flow Systems, Springer, Netherlands, Dordrecht (2005), pp. 223-251. CrossRef Google Scholar. Tang and Johannesson, 2010. J. Tang, K.H. Johannesson. Ligand

    Hydrogeochemistry and fractionation of boron isotopes in

    01.04.2021· Groundwater flow systems can be topography-controlled in arid, mountainous, and/or permeable areas. Previous theoretical studies indicated that local groundwater flow systems were usually less developed or even did not exist in recharge-controlled flow systems, and the whole flow system was dominated by regional groundwater flow system.

    Isotopic Fractionation of U in Rocks Reflecting Redox

    07.05.2021· Isotopic Fractionation of U in Rocks Reflecting Redox Conditions around a Groundwater Flow Route Juhani Suksi1 and Kari Rasilainen2 1 Laboratory of Radiochemistry, University of Helsinki, Finland 2 VTT Energy, Espoo, Finland ABSTRACT Low 234U/238U activity ratios observed in rock and mineral samples were scrutinized. U

    Chromium Isotope Fractionation During Reduction of

    Chromium isotopes are potentially useful indicators of Cr(VI) reduction reactions in groundwater flow systems; however, the influence of transport on Cr isotope fractionation has not been fully examined. Laboratory batch and column experiments were conducted to evaluate isotopic fractionation of Cr during Cr(VI) reduction under both static and controlled flow conditions. Organic carbon was

    U isotopic fractionation — a process characterising

    Abstract. The activity of 234 U relative to 238 U (AR) in groundwaters is controlled by isotope fractionation in water-rock interface. The fractionation is controlled by redox-conditions and rock-groundwater contact time. The measured ARs form thus an important source of information and offer an effective tool to characterise groundwater systems along with other hydrochemical data.

    ER21-5124 Project Overview SERDP-ESTCP

    Low-Cost, Passive In Situ Treatment of PFAS-Impacted Groundwater Using Foam Fractionation In an Air Sparge Trench. Dung Nguyen CDM Smith ER21-5124. Objective Technology Benefits; Objective. The overarching goal of this project is to demonstrate and validate the use of a novel remedial technology capable of passively treating per- and polyfluoroalkyl substance (PFAS)-impacted groundwater

    Role of Manganese Oxyhydroxides in the Transport of Rare

    26.06.2019· which REE groundwater patterns depend on fractionation by HMO. Therefore, the objectives of this study are to (i) identify the roles of HMO in transport of REE in groundwater along the flow path; (ii) quantitatively determine REE surface complexation reactions with HMO in groundwater from di erent aquifers; and (iii) evaluate the influence of HMO concentrations on REE speciation and

    Chapter 2: Fundamentals of Isotope Geochemistry

    These result from runoff mechanisms that include, but are not limited to, saturation-excess overland flow, Hortonian overland flow, near-stream groundwater ridging, hillslope subsurface flow through the soil matrix or macropores, and shallow organic-layer flow. Knowledge of hydrologic flowpaths in catchments is critical to the preservation of public water supplies and the understanding of the

    Isotope hydrology: Investigating groundwater contamination

    Investigating groundwater contamination Environmental isotopes are used to study serious pollution problems by V. Dubinchuk, K. Frohlich, and R. Gonfiantini During the past 100 years, groundwater has become an increasingly important source of water supply world-wide for domestic, agricultural, and industrial uses. The almost ubiquitous occurrence of water-bearing forma-tions, the quality of

    Modeling isotope fractionation in heterogeneous

    MODFLOW was used to develop a two-dimensional groundwater flow model, and chemical reduction was incorporated into the model using MT3D. Preliminary simulations with reaction occurring only in certain restricted domains show strongly decreased effective isotopic shifts for any given extent of reaction, relative to that produced by Rayleigh models for the same extent of reaction in a

    U isotopic fractionation — a process characterising

    Abstract. The activity of 234 U relative to 238 U (AR) in groundwaters is controlled by isotope fractionation in water-rock interface. The fractionation is controlled by redox-conditions and rock-groundwater contact time. The measured ARs form thus an important source of information and offer an effective tool to characterise groundwater systems along with other hydrochemical data.

    Isotope Fractionation of Toluene: A Perspective to

    the groundwater flow path indicates microbial degradation processes and can be used as an indicator for in situ biodegradation. The Rayleigh equation was applied to calculate the percentage of the in situ biodegradation (B[%]) using the change in the isotopic composition of contaminants (R t /R 0) along the ground water flow path and a kinetic carbon isotope fractionation factor ( aC) derived

    Comparative study of granitic and sedimentary

    Comparative study of granitic and sedimentary groundwater colloids by flow field flow fractionation coupled with ICP-MS Colloids in deep underground water play an importance role in the migration of radionuclides and of great concern in the safety assessment of geological disposal of nuclear wastes.

    (PDF) Isotope fractionation of toluene: a perspective to

    A concept to assess in situ biodegradation of organic contaminants in aquifers is presented. The alteration of the carbon isotope composition of contaminants along the groundwater flow path indicates microbial degradation processes and can be used as

    Characterization of Suboxic Groundwater Colloids

    Anoxic groundwater colloid properties were measured using a minimally perturbing procedure for sampling, processing, and analysis. Analytical methods included atomic force microscopy (AFM), flow field flow fractionation (FlFFF), and transmission and scanning electron microscopy (TEM and SEM). Shallow groundwater samples showed abundant iron rich nanoparticles (NP) with diameters of

    Asymmetrical flow field-flow fractionation coupled with a

    Abstract This paper describes an asymmetrical flow field-flow fractionation (AF4) technique combined with a flow-through cell having a long optical path length, called a liquid waveguide capillary cell (LWCC). The performance of the AF4-LWCC system for separation and spectrophotometric detection of nanoparticles was examined using size-standard silver nanoparticles.

    Flow field-flow fractionation (FlFFF) coupled to sensitive

    Flow field-flow fractionation (FlFFF) coupled to sensitive detection techniques: a way to examine radionuclide interactions with nanoparticles Volume 76 Issue 7

    Chapter 2: Fundamentals of Isotope Geochemistry

    These result from runoff mechanisms that include, but are not limited to, saturation-excess overland flow, Hortonian overland flow, near-stream groundwater ridging, hillslope subsurface flow through the soil matrix or macropores, and shallow organic-layer flow. Knowledge of hydrologic flowpaths in catchments is critical to the preservation of public water supplies and the understanding of the

    Isotope hydrology Wikipedia

    Isotope hydrology is a field of geochemistry and hydrology that uses naturally occurring stable and radioactive isotopic techniques to evaluate the age and origins of surface and groundwater and the processes within the atmospheric hydrologic cycle. Isotope hydrology applications are highly diverse, and used for informing water-use policy, mapping aquifers, conserving water supplies, assessing

    Comparative study of granitic and sedimentary

    Comparative study of granitic and sedimentary groundwater colloids by flow field flow fractionation coupled with ICP-MS Colloids in deep underground water play an importance role in the migration of radionuclides and of great concern in the safety assessment of geological disposal of nuclear wastes.

    Soil and Groundwater Equipment for Field-flow

    Results for soil and groundwater equipment with field-flow fractionation (fff) solutions for biopolymers of food-agro-cosmetics applications from Postnova and other leading brands. Compare and contact a supplier near you

    Characterization of aquatic groundwater colloids by a

    Characterization of aquatic groundwater colloids by a laser-induced breakdown detection and ICP-MS combined with an asymmetric flow field-flow fractionation

    Isotopic fractionation of U in rocks reflecting redox

    Low 234 U/ 238 U activity ratios observed in rock and mineral samples were scrutinized. U isotope fractionation leading to 234 U depletion (234 U/ 238 U<1) in rocks appears to be linked to changes in redox conditions. The fractionation takes place as selective chemical release dominates over direct physical μ recoil. This preferential 234 U release depends on the valence contrast between the

    Flow field-flow fractionation (FlFFF) coupled to sensitive

    Flow field-flow fractionation (FlFFF) coupled to sensitive detection techniques: a way to examine radionuclide interactions with nanoparticles Volume 76 Issue 7

    Role of Manganese Oxyhydroxides in the Transport of Rare

    26.06.2019· which REE groundwater patterns depend on fractionation by HMO. Therefore, the objectives of this study are to (i) identify the roles of HMO in transport of REE in groundwater along the flow path; (ii) quantitatively determine REE surface complexation reactions with HMO in groundwater from di erent aquifers; and (iii) evaluate the influence of HMO concentrations on REE speciation and

    Stable Isotope Fractionation by Transport and

    Stable Isotope Fractionation by Transport and Transformation Jennifer L. Druhan; Jennifer L. Druhan Department of Geology, University of Illinois Urbana Champaign, Urbana, Illinois, 61801, USA. [email protected] Search for other works by this author on: GSW. Google Scholar

    HESS A review of methods for measuring groundwater

    Riegler (2012) examined groundwater levels, in conjunction with flow gauging, in the North Branch of the Ashburton River in Canterbury, New Zealand, to attempt to correlate groundwater levels and decreased flow levels in the river. The study concluded that there were too many uncertainties, particularly around the complex behaviour of the groundwater system, to draw strong conclusions on

    Isotope hydrology Wikipedia

    Isotope hydrology is a field of geochemistry and hydrology that uses naturally occurring stable and radioactive isotopic techniques to evaluate the age and origins of surface and groundwater and the processes within the atmospheric hydrologic cycle. Isotope hydrology applications are highly diverse, and used for informing water-use policy, mapping aquifers, conserving water supplies, assessing

    (PDF) Monitoring in situ biodegradation of benzene and

    Monitoring in situ biodegradation of benzene and toluene by stable carbon isotope fractionation. Environmental Toxicology and Chemistry, 2005. Hans Richnow. Rainer Meckenstock + 9 More. Hans Richnow. Rainer Meckenstock. Rainer Meckenstock. Rainer Meckenstock. R. Meckenstock. R. Meckenstock. Matthias Kästner. Mario Schirmer. H. Weiss . Kristin Schirmer. andrea vieth-hillebrand.

 

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